Zeros of a binomial combination of Chebyshev polynomials

For [Formula: see text], we study the zeros of the sequence of polynomials [Formula: see text] generated by the reciprocal of [Formula: see text], expanded as a power series in [Formula: see text]. Equivalently, this sequence is obtained from a linear combination of Chebyshev polynomials whose coefficients have a binomial form. We show that the number of zeros of [Formula: see text] outside the interval [Formula: see text] is bounded by a constant independent of [Formula: see text].

Exponentially faster implementations of Select(H) for fermionic Hamiltonians

We present a simple but general framework for constructing quantum circuits that implement the multiply-controlled unitary Select(H):=∑ℓ|ℓ⟩⟨ℓ|⊗Hℓ, where H=∑ℓHℓ is the Jordan-Wigner transform of an arbitrary second-quantised fermionic Hamiltonian. Select(H) is one of the main subroutines of several quantum algorithms, including state-of-the-art techniques for Hamiltonian simulation. If each term in the second-quantised Hamiltonian involves at most k spin-orbitals and k is a constant independent of the total number of spin-orbitals n (as is the case for the majority of quantum chemistry and condensed matter models considered in the literature, for which k is typically 2 or 4), our implementation of Select(H) requires no ancilla qubits and uses O(n) Clifford+T gates, with the Clifford gates applied in O(log2n) layers and the T gates in O(logn) layers. This achieves an exponential improvement in both Clifford- and T-depth over previous work, while maintaining linear gate count and reducing the number of ancillae to zero.

Quantum Hall effect and von Klitzing constant

The current problem in the field of electrical measurements is considered in connection with the new definitions of SI units of physical quantities adopted by the 26th General Conference on Weights and Measures in November 2018 (France, Versailles), namely, the reproduction of an ohm based on the quantum Hall effect. The reasons for the introduction in 1988 of the Klitzing constant independent of the international system of units and its cancellation in 2018 are explained. The physical foundations of the quantum Hall effect are outlined. The main indirect and direct experiments that led to the creation of an ohm standard based on the quantum Hall effect, including those carried out at VNIIMS in 1982–1986, are analyzed. Using the example of these experiments, the identity of the values of the quantized resistance for samples prepared on the basis of inversion layers in silicon, gallium arsenide and in samples of a fundamentally new substance graphene is shown. Results on the use of graphene to create standards based on the quantum Hall effect for various industries and science based on the latest advances in its production are presented.

A simplified disproof of Beck’s three permutations conjecture and an application to root-mean-squared discrepancy

A k-permutation family on n vertices is a set-system consisting of the intervals of k permutations of the integers 1 to n. The discrepancy of a set-system is the minimum over all red–blue vertex colourings of the maximum difference between the number of red and blue vertices in any set in the system. In 2011, Newman and Nikolov disproved a conjecture of Beck that the discrepancy of any 3-permutation family is at most a constant independent of n. Here we give a simpler proof that Newman and Nikolov’s sequence of 3-permutation families has discrepancy $\Omega (\log \,n)$ . We also exhibit a sequence of 6-permutation families with root-mean-squared discrepancy $\Omega (\sqrt {\log \,n} )$ ; that is, in any red–blue vertex colouring, the square root of the expected squared difference between the number of red and blue vertices in an interval of the system is $\Omega (\sqrt {\log \,n} )$ .

Renaissance educational guidelines of the «Ideal governor» training in «Song of the bison» by Belarusian thinker Mykola Husovsky

The article is devoted to the coverage of the main Renaissance educational guidelines for the training of the «ideal governor» in the «Song of the bison» by Belarusian thinker Mykola Husovsky, who lived in the XV – XVIth centuries. In particular, author's allusions and metaphors of the words «bison» and «ideal governor», «forest dwellers» and society were analyzed. It was characterized the author 's ideas about the statesman' s training including the necessity of the development of integrity, sincerity, moderation, wisdom, justice etc of a student . At the same time, it was found that a representative of the East Slavic ethno-cultural environment Husovsky was concentrated on a common European humanistic mainstream. This is specified in the inheritance of titles and regalia, honor and high morality, aesthetization and liberalization of educational influences on the individual in the conditions of constant independent hard work over the representatives of the political establishment of that time in Europe.

Spectrum perturbations of compact operators in a Banach space

For an integer p ≥ 1, let Γp be an approximative quasi-normed ideal of compact operators in a Banach space with a quasi-norm NΓp(.) and the property $$\begin{array}{} \displaystyle \sum_{k=1}^{\infty} |\lambda_k(A)|^p\le a_p N_{{\it\Gamma}_p}^p(A) \;\;(A\in {\it\Gamma}_p), \end{array}$$ where λk(A) (k = 1, 2, …) are the eigenvalues of A and ap is a constant independent of A. Let A, Ã ∈ Γp and $$\begin{array}{} \displaystyle {\it\Delta}_p(A, \tilde A):= N_{{\it\Gamma}_p}(A-\tilde A) \;\exp\;\left[a_p b_p^p \;\left(1+\frac{1}2 (N_{{\it\Gamma}_p}(A+\tilde A) + N_{{\it\Gamma}_p}(A-\tilde A))\right)^p\right], \end{array}$$ where bp is the quasi-triangle constant in Γp. It is proved the following result: let I be the unit operator, I – Ap be boundedly invertible and $$\begin{array}{} \displaystyle {\it\Delta}_p(A, \tilde A)\exp\;\left[\frac{a_pN^p_{{\it\Gamma}_p}(A) } {\psi_p(A)}\right] \lt 1, \end{array}$$ where ψp(A) = infk=1,2,… |1 – $\begin{array}{} \displaystyle \lambda_k^{p} \end{array}$(A)|. Then I – Ãp is also boundedly invertible. Applications of that result to the spectrum perturbations of absolutely p-summing and absolutely (p, 2) summing operators are also discussed. As examples we consider the Hille-Tamarkin integral operators and matrices.

On the Number of p4-Tilings by an n-Omino

A plane tiling by the copies of a polyomino is called isohedral if every pair of copies in the tiling has a symmetry of the tiling that maps one copy to the other. We show that, for every [Formula: see text]-omino (i.e., polyomino consisting of [Formula: see text] cells), the number of non-equivalent isohedral tilings generated by 90 degree rotations, so called p4-tilings or quarter-turn tilings, is bounded by a constant (independent of [Formula: see text]). The proof relies on the analysis of the factorization of the boundary word of a polyomino. We also show an example of a polyomino that has three non-equivalent p4-tilings.

14-point difference operator for the approximation of the first derivatives of a solution of Laplace’s equation in a rectangular parallelepiped

A 14-point difference operator is used to construct finite difference problems for the approximation of the solution, and the first order derivatives of the Dirichlet problem for Laplace?s equations in a rectangular parallelepiped. The boundary functions ?j on the faces ?j, j = 1,2,...,6 of the parallelepiped are supposed to have pth order derivatives satisfying the H?lder condition, i.e., ?j ? Cp,?(?j), 0 < ? < 1, where p = {4,5}. On the edges, the boundary functions as a whole are continuous, and their second and fourth order derivatives satisfy the compatibility conditions which result from the Laplace equation. For the error uh - u of the approximate solution uh at each grid point (x1,x2,x3), ?uh-u?? c?p-4(x1,x2,x3)h4 is obtained, where u is the exact solution, ? = ? (x1, x2,x3) is the distance from the current grid point to the boundary of the parallelepiped, h is the grid step, and c is a constant independent of ? and h. It is proved that when ?j ? Cp,?, 0 < ? < 1, the proposed difference scheme for the approximation of the first derivative converges uniformly with order O(hp-1), p ? {4,5}.

A quantitative isoperimetric inequality on the sphere

In this paper we prove a quantitative version of the isoperimetric inequality on the sphere with a constant independent of the volume of the set E.

ALGORITHMS FOR CONSTRUCTING EDGE MAGIC TOTAL LABELING OF COMPLETE BIPARTITE GRAPHS

The study of graph labeling has focused on finding classes of graphs which admits a particular type of labeling. In this paper we consider a particular class of graphs which demonstrates Edge Magic Total Labeling. The class we considered here is a complete bipartite graph Km,n. There are various graph labeling techniques that generalize the idea of a magic square has been proposed earlier. The definition of a magic labeling on a graph with v vertices and e edges is a one to one map taking the vertices and edges onto the integers 1,2,3,………, v+e with the property that the sum of the label on an edge and the labels of its endpoints is constant independent of the choice of edge. We use m x n matrix to construct edge magic total labeling of Km,n.